In the fields of biotechnology and health care, attention has recently been paid to a semiconductor analysis chip wherein microfluidic device, such as a micro flow channel and a detection mechanism, are integrated. In this type of chips, a sample liquid is poured into a channel, and a change in an electrical signal is detected when a particle of the sample liquid passes through a micropore formed in the channel. From the change, a particle or biopolymer in the liquid can be detected.